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Commit b9b6b68e authored by Björn Töpel's avatar Björn Töpel Committed by Alexei Starovoitov
Browse files

xsk: add Rx queue setup and mmap support 



Another setsockopt (XDP_RX_QUEUE) is added to let the process allocate
a queue, where the kernel can pass completed Rx frames from the kernel
to user process.

The mmapping of the queue is done using the XDP_PGOFF_RX_QUEUE offset.

Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 423f3832

include/net/xdp_sock.h

+4 −0
Original line number Diff line number Diff line
@@ -18,11 +18,15 @@ 
#include <linux/mutex.h>

#include <net/sock.h>



struct net_device;

struct xsk_queue;

struct xdp_umem;



struct xdp_sock {

	/* struct sock must be the first member of struct xdp_sock */

	struct sock sk;

	struct xsk_queue *rx;

	struct net_device *dev;

	struct xdp_umem *umem;

	/* Protects multiple processes in the control path */

	struct mutex mutex;

include/uapi/linux/if_xdp.h

+16 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/types.h>



/* XDP socket options */

#define XDP_RX_RING			1

#define XDP_UMEM_REG			3

#define XDP_UMEM_FILL_RING		4
@@ -33,13 +34,28 @@ struct xdp_umem_reg { 
};



/* Pgoff for mmaping the rings */

#define XDP_PGOFF_RX_RING			  0

#define XDP_UMEM_PGOFF_FILL_RING	0x100000000



struct xdp_desc {

	__u32 idx;

	__u32 len;

	__u16 offset;

	__u8 flags;

	__u8 padding[5];

};



struct xdp_ring {

	__u32 producer __attribute__((aligned(64)));

	__u32 consumer __attribute__((aligned(64)));

};



/* Used for the RX and TX queues for packets */

struct xdp_rxtx_ring {

	struct xdp_ring ptrs;

	struct xdp_desc desc[0] __attribute__((aligned(64)));

};



/* Used for the fill and completion queues for buffers */

struct xdp_umem_ring {

	struct xdp_ring ptrs;

net/xdp/xsk.c

+32 −9
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/net.h>

#include <linux/netdevice.h>

#include <net/xdp_sock.h>

#include <net/xdp.h>



#include "xsk_queue.h"

#include "xdp_umem.h"
@@ -40,14 +41,15 @@ static struct xdp_sock *xdp_sk(struct sock *sk) 
	return (struct xdp_sock *)sk;

}



static int xsk_init_queue(u32 entries, struct xsk_queue **queue)

static int xsk_init_queue(u32 entries, struct xsk_queue **queue,

			  bool umem_queue)

{

	struct xsk_queue *q;



	if (entries == 0 || *queue || !is_power_of_2(entries))

		return -EINVAL;



	q = xskq_create(entries);

	q = xskq_create(entries, umem_queue);

	if (!q)

		return -ENOMEM;
@@ -89,6 +91,22 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname, 
		return -ENOPROTOOPT;



	switch (optname) {

	case XDP_RX_RING:

	{

		struct xsk_queue **q;

		int entries;



		if (optlen < sizeof(entries))

			return -EINVAL;

		if (copy_from_user(&entries, optval, sizeof(entries)))

			return -EFAULT;



		mutex_lock(&xs->mutex);

		q = &xs->rx;

		err = xsk_init_queue(entries, q, false);

		mutex_unlock(&xs->mutex);

		return err;

	}

	case XDP_UMEM_REG:

	{

		struct xdp_umem_reg mr;
@@ -130,7 +148,7 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname, 


		mutex_lock(&xs->mutex);

		q = &xs->umem->fq;

		err = xsk_init_queue(entries, q);

		err = xsk_init_queue(entries, q, true);

		mutex_unlock(&xs->mutex);

		return err;

	}
@@ -151,6 +169,9 @@ static int xsk_mmap(struct file *file, struct socket *sock, 
	unsigned long pfn;

	struct page *qpg;



	if (offset == XDP_PGOFF_RX_RING) {

		q = xs->rx;

	} else {

		if (!xs->umem)

			return -EINVAL;
@@ -158,6 +179,7 @@ static int xsk_mmap(struct file *file, struct socket *sock, 
			q = xs->umem->fq;

		else

			return -EINVAL;

	}



	if (!q)

		return -EINVAL;
@@ -205,6 +227,7 @@ static void xsk_destruct(struct sock *sk) 
	if (!sock_flag(sk, SOCK_DEAD))

		return;



	xskq_destroy(xs->rx);

	xdp_put_umem(xs->umem);



	sk_refcnt_debug_dec(sk);

net/xdp/xsk_queue.c

+9 −2
Original line number Diff line number Diff line
@@ -21,7 +21,13 @@ static u32 xskq_umem_get_ring_size(struct xsk_queue *q) 
	return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u32);

}



struct xsk_queue *xskq_create(u32 nentries)

static u32 xskq_rxtx_get_ring_size(struct xsk_queue *q)

{

	return (sizeof(struct xdp_ring) +

		q->nentries * sizeof(struct xdp_desc));

}



struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)

{

	struct xsk_queue *q;

	gfp_t gfp_flags;
@@ -36,7 +42,8 @@ struct xsk_queue *xskq_create(u32 nentries) 


	gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |

		    __GFP_COMP  | __GFP_NORETRY;

	size = xskq_umem_get_ring_size(q);

	size = umem_queue ? xskq_umem_get_ring_size(q) :

	       xskq_rxtx_get_ring_size(q);



	q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,

						      get_order(size));

net/xdp/xsk_queue.h

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ struct xsk_queue { 
	u64 invalid_descs;

};



struct xsk_queue *xskq_create(u32 nentries);

struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);

void xskq_destroy(struct xsk_queue *q);



#endif /* _LINUX_XSK_QUEUE_H */